The discussion revolves around the expression for torque on a dipole in an external electric field, specifically questioning why the expression is represented as PxE rather than ExP. Participants are exploring the implications of vector cross products in this context.
The discussion is ongoing, with participants examining the definitions of vector directions and their implications for torque and angular quantities. There is a recognition of the importance of coordinate systems in determining positive and negative directions.
Participants are considering the assumptions related to vector quantities and the definitions of positive or negative directions within their chosen coordinate systems.
What's the essential difference in the cross products A x B versus B x A?Prashasti said:Homework Statement
Why isn't the expression for torque on a dipole kept in an external electric field ExP? Why is it PxE?
No such indication has been given in any of the derivations, that it is mandatory for it to be PxE, so why can't it be ExP?
2. The attempt at a solution
Is it all about experiments?
Right. So it comes down to the definitions of positive or negative directions for quantities in the chosen coordinate system. This includes assumed directions for positive or negative torques, angular velocities, etc., which are vector quantities (or pseudo vector quantities in some cases, but that's another topic).Prashasti said:The direction of the resultant of A x B is just opposite to that of B x A...